The invention relates to a wheel, particularly a light metal wheel for motor vehicles wherein each such wheel comprises a spoke wheel center and a wheel rim, in which the wheel rim has an inner bead seat making a transition to an internal horn of the rim, and an outer bead seat making a transition into an external horn of the rim.
Such types of wheels enjoy very great popularity, particularly in a construction as light metal wheels, since, in addition to an increased overall aesthetic appearance of the motor vehicle, additional technical advantages can be attained.
In entirely general terms, the present trend is towards reducing the weight of the wheel as much as possible. This is an additional reason for the increasing spread of light metal wheels. The savings in weight relative to conventional steel wheels that is achieved is frequently not very high, however, since the light metal alloys that are used mostly do not have the strength of steel. Such wheels must therefore be designed with greater wall thicknesses, as the result of which the weight advantage is partially lost again.
The task which forms the basis for the present invention is therefore that of further developing a wheel, particularly a light metal wheel for motor vehicles, in such a manner that it no longer has the disadvantages stated. In particular, a wheel should be created which permits an additional reduction of weight or an improvement of the mechanical characteristics relative to conventional wheels.
This problem is solved by means of a wheel which is provided with profile segments which continuously form at least one hollow chamber in the direction of the circumference, which profile segments, at least in sections, are provided in the area of the internal bead seat and the external bead seat.
Advantageous forms of implementation of the invention are also stated herein.
The invention is based on the idea of forming hollow chambers in areas of the wheel that are subject to particularly heavy stresses, thus, in the area of the internal horn of the rim and the external horn of the rim.
These hollow chambers are comparable with closed hollow chamber profile sections, which are known entirely generally from the area of light construction and which permit a considerable increase in the strength. In concrete terms, it is provided to apply profile segments, which each form hollow chambers in the direction of circumference, in the area of the internal base of the rim and/or of the external base of the rim. As a general rule, the hollow chamber is developed continuously in the direction of circumference, so that an increase in rigidity, distributed optimally uniformly over the circumference, is provided. In the area of the internal horn of the rim, the increase in the bending strength is used to improve the so-called impact behavior. In the area of the external horn of the rim, the aspect of the weight reduction is most prominent.
One particularly weight-saving construction results if the hollow chamber assigned to the external base of the rim is combined with hollow chamber spokes. In this manner, a hollow chamber structure, which makes possible excellent rigidity values with simultaneously minimum weight, can be provided.
The construction of the hollow chambers is carried out by means of profile segments which are attached to the wheel rim in the area of the internal base of the rim or of the external base of the rim and are connected into a closed hollow profile.
One particularly simple construction results if the profile segments are developed as shell units, particularly as half-shell units. These can be pre-manufactured in a simple way and manner and, as a rule, applied to the external circumference of the wheel rim. The individual segments can be connected with one another by means of connection techniques which are known per se and have already proven their value, such as welding, adhesion, or flanging, for example. The connection is likewise carried out towards the wheel rim, so that a closed hollow chamber profile can be produced.
The geometrical configuration of the profile segments can be selected in such a manner that optimal results can be achieved in relation to the bending strength that is being striven for. As a rule, however, at least one section of the specific profile segments of the base of the rimxe2x80x94that is to say, the internal base of the rim or the external base of the rimxe2x80x94is configured so that the geometry is accordingly provided in those areas as a seat or supporting surface for the tires.
In accordance with one preferred variant, the profile segments are developed in a congruent manner in the area of the internal base of the rim and the profile segments in the area of the external base of the rim. They can consequently be stored in inventory as so-called identical parts, and permit optional application in the internal- or in the external area.
Finally, it is also possible to form the profile segments, by means of a non-cutting shaping process, from an annular bar integrally formed on the wheel rim, particularly one cast integrally in a single piece. So-called ductile materials, which can be transformed under cold conditions, or cast alloys, which can be transformed under warm conditions, are suited for this.